In 1959, Schirra was selected as a Project Mercury astronaut. His responsibility, in addition to training for space flights, was the development and testing of the astronauts' life-support systems.
Schirra was a practical joker, relaxed and popular with his fellow astronauts. But he also was tough, cool and decisive under pressure. He became an outspoken critic of the carefully choreographed public relations program that threatened to smother the astronauts.
"None of us is interested in the glamour of being a spaceman," he said. "We're interested in getting up, and getting back."
Schirra got up and back three times, once each during the Mercury, Gemini and Apollo programs. During his second space flight, maneuvering at 17,000 mph under Schirra's direction, Gemini 6 and Gemini 7 circled for hours, perfecting the techniques that would enable later space vehicles to dock with one another during flights to the moon.
Despite the danger, the banter never stopped.
"There seems to be a lot of traffic up here," Schirra radioed from Gemini 6 after one particularly close maneuver.
"Call a policeman," Borman retorted from Gemini 7.
"I can see your lips moving," Gemini 7 pilot Lovell told Schirra.
"I'm chewing gum," Schirra replied.
In 1969, after receiving the Robert J. Collier Trophy, the nation's highest honor for achievement in aviation, Schirra left NASA and the Navy. He became a commentator for CBS News and often teamed up with anchorman Walter Cronkite on space coverage.
He held executive positions with Regency Investors, the ECCO Corp., Sernco, Johns-Mansville, Goodwin Cos. and Kimberly-Clark, retiring from the business world in the late 1970s.
In recent years, Schirra lived in Rancho Santa Fe, Calif., emerging now and then for speaking appearances and interviews with the media. There was always an audience for a space pioneer, one who looked down as well as up.
"I look back on those missions and I remember looking at the spaceship Earth," he told a reporter in 1998. "It's the most beautiful thing I've ever seen. We need to take care of it."
Survivors include his wife, Josephine; daughter Suzanne; and son Walter Schirra III.